The invention relates to a method for making for a microwave corrugated-horn antenna using waveguide technology.
This type of antenna is generally made up of several molded parts. In particular, for making the corrugated horn, the process consists in molding two half-parts that are symmetrical relative to an axial plane of the horn. The number of molds required for the manufacture of the various elements of such an antenna can become prohibitive with a view to high-volume, low-cost production. Moreover, the alignment and interconnection of the various elements of the antenna, in order to limit the electrical discontinuities, lead to manufacturing constraints that impact the production cost of the antenna.
FIG. 1 shows a perspective view of an example of a microwave antenna using waveguide technology comprising a corrugated horn 1 with, amongst other features, a frequency separator 2. The corrugated horn 1 is formed by assembly of two symmetrical half-parts.
The use of blocks of synthetic foam, such as polymethacrylimide, for constructing microwave devices using waveguide technology is known from the document “Foam technology for integration of microwave 3D functions”—ELECTRONICS LETTERS 14 Oct. 1999—Vol. 35 No21. In particular, this document proposes the construction of a 3D bandpass filter by molding of a block of foam.
A process for depositing a metallic film onto a block of foam for manufacturing microwave antennas using waveguide technology is also known from the French patent document no2780319.
The aim of the invention is to propose a process for manufacturing, from a block of synthetic foam, a microwave corrugated-horn antenna using waveguide technology, which process is designed for low-cost volume production, but which avoids the drawbacks indicated above.
The process according to the invention consists in forming the corrugations of the horn on the external surface of a block of synthetic foam and in subsequently metallizing the surface of the conformed block of foam to form the antenna. With this process, the corrugated horn can be manufactured as a single piece, which will contribute to eliminate the electrical discontinuities in the antenna.